{"app_store_id":1673640297,"slug":"scientific-calculator-fx-991-1673640297","name":"Scientific Calculator fx-991","short_name":"Scientific Calculator fx-991","subtitle":"Step-by-step Math Solver","icon_url":"https://is1-ssl.mzstatic.com/image/thumb/Purple211/v4/0e/b0/3b/0eb03be1-48d3-07a1-0c87-e9092eb8a5f0/AppIcon-0-0-1x_U007emarketing-0-8-0-85-220.png/512x512bb.jpg","icon_tint":"#aa8757","store_url":"https://apps.apple.com/us/app/scientific-calculator-fx-991/id1673640297?uo=4","price":0,"currency":"USD","rating":4.58186,"rating_count":452,"rating_worldwide":4.696,"rating_count_worldwide":7500,"in_app_purchases":true,"recent_rating":null,"recent_review_count":null,"reviews_checked_at":null,"primary_genre":"Education","version_date":"2026-10-23T16:26:28Z","updated_at":"2026-11-13T09:27:12.662Z","stale":false,"missing_since":null,"one_liner":"Scientific calculator app with a step-by-step equation solver, graphing mode, formula library and unit converter.","verified_maker":false,"maker_site":null,"file_size_bytes":28155904,"minimum_os":"15.0","content_rating":"4+","language_count":59,"screenshots":["https://is1-ssl.mzstatic.com/image/thumb/PurpleSource221/v4/19/5e/ea/195eeaab-0b60-4dcd-6f5b-355fad6b24e4/8403663f-a2ba-40b0-87e6-fbd5ff3cbc56_a1_55_en.png/392x696bb.png","https://is1-ssl.mzstatic.com/image/thumb/PurpleSource221/v4/e1/4f/dc/e14fdca2-7c78-7a0d-b942-b15dc4882723/eb376edf-69b6-4a20-9497-df6fc315150d_a2_55_en.png/392x696bb.png","https://is1-ssl.mzstatic.com/image/thumb/PurpleSource211/v4/c2/bc/83/c2bc833f-023b-3afe-3ce6-ddaf42ac88de/9c774fd5-1d81-4230-9c5f-634d10b73114_3en.png/392x696bb.png","https://is1-ssl.mzstatic.com/image/thumb/PurpleSource221/v4/44/95/5a/44955a5b-a242-76be-292a-4caf3d1209f8/245bde3a-621a-4d17-a297-bdea19c5efb0_ls_en.png/392x696bb.png","https://is1-ssl.mzstatic.com/image/thumb/PurpleSource221/v4/d8/48/66/d84866f1-12b4-7aa5-ea21-c363f688ff32/ecda7d29-982c-4276-bb42-438733f800c1_anh_chuyen_doi_en.png/392x696bb.png","https://is1-ssl.mzstatic.com/image/thumb/Purple211/v4/b0/55/89/b055894f-8e7f-c02b-3faa-6728bea3f15f/00c597bc-ec4b-4325-a199-12d3aadbe150_Untitled1.png/392x696bb.png","https://is1-ssl.mzstatic.com/image/thumb/Purple211/v4/97/21/99/97219905-3c65-102e-7828-358656d6279c/cae189aa-6d37-46a8-a072-de16449deaf7_Untitled2.png/392x696bb.png"],"developer_name":"Dinh Phuc","editors_choice":false,"url":"https://apptierlist.com/apps/scientific-calculator-fx-991-1673640297/","api_url":"https://apptierlist.com/api/v1/apps/scientific-calculator-fx-991-1673640297","schema_version":"1.0","generated_at":"2026-11-14T17:40:17.557Z","data_as_of":"2026-11-14T15:21:12.738Z","description":"Scientific Calculator fx-991 – The Ultimate Math & Science Tool!\nStruggling with math problems, equations, or integrals?  Need a powerful scientific calculator to solve step-by-step?\n\nWith Scientific Calculator fx-991, you can calculate, graph, and find formulas instantly – making learning math, physics, and chemistry easier than ever! \n\nKey Features\n+ Step-by-step equation solver – Enter any equation and get a detailed step-by-step solution.\n+ Advanced scientific functions – Solve fractions, algebra, derivatives, integrals, trigonometry, and more.\n+ Graphing mode – Visualize mathematical functions interactively.\n+ Extensive formula library – Access key formulas for math, physics, and chemistry in seconds.\n+ Unit converter – Quickly convert between different measurement units.\n+ Casio fx-991 inspired interface – A familiar and intuitive experience for students.\n\n Perfect for high school and college students, engineers, and professionals in STEM fields!\n\n Who is this app for?\nHigh school students – Solve algebra, calculus, and physics problems efficiently.\n College & university students – Master engineering, physics, and complex math subjects.\n STEM professionals – Perform advanced calculations quickly and accurately.\n\n Download Scientific Calculator fx-991 now and simplify your calculations! \nTerms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/.","facts":{"developer_id":1673640299,"developer_url":"https://hiedu.vn/","first_released":"2023-02-28T08:00:00Z","support_url":"https://hiedu.vn/","privacy_url":"http://xn--ngdungtt-b4a68p.vn/policy_calculator.html","website_url":"https://hiedu.vn/","app_version":"1.9.3","release_notes":"- Added Daily Challenge with 10 new math questions every day.\n- Track your personal progress and compete on the 7-day leaderboard.","rating_current_version":4.58186,"rating_count_current_version":452,"star_counts":[24,10,11,41,364],"genres":["Education"],"languages":["AF","SQ","AR","HY","AZ","EU","BE","BG","CA","HR","CS","DA","NL","EN","ET","FI","FR","GL","KA","DE","EL","GU","HE","HI","HU","IS","ID","IT","JA","KN","KK","KO","KY","LV","LT","MK","MS","ML","MN","NE","NB","FA","PL","PT","RO","RU","SR","ZH","SI","SK","SL","ES","SV","TH","TR","UK","UR","VI","ZU"],"content_advisories":null,"device_families":["iphone","ipad","ipod"],"made_for_iphone_duo":false,"chart":null},"freshness":{"apple_read_at":"2026-11-13T09:27:12.662Z","catalog_read_at":"2026-11-06T12:47:13.011Z","reviews_checked_at":null,"summary_written_at":"2026-11-06T08:41:13.186Z","placed_at":"2026-11-06T09:13:12.903Z","scored_at":"2026-11-14T15:21:12.738Z"},"editorial":{"one_liner":"Scientific calculator app with a step-by-step equation solver, graphing mode, formula library and unit converter.","what_is":"Scientific Calculator fx-991 is an education app for calculating, graphing and looking up formulas in math, physics and chemistry. Its listed features include an equation solver that shows step-by-step solutions, support for functions such as integrals and derivatives, and a unit converter. The interface is described as inspired by the Casio fx-991.","good_for":["Checking algebra, calculus or trigonometry homework step by step","Graphing functions interactively while studying","Converting units and looking up formulas for physics or chemistry"],"pricing":"Scientific Calculator fx-991 is free to download, with in-app purchases on the App Store.","faq":[{"q":"Is the app free?","a":"It is free to download."},{"q":"Does it show steps for solving equations?","a":"Yes. The step-by-step equation solver lets you enter an equation and get a detailed step-by-step solution."},{"q":"Who is the app intended for?","a":"The listing names high school students, college and university students, and STEM professionals as its intended users."}],"model":"claude-haiku-5-5","created_at":"2026-11-06T08:41:13.186Z"},"memberships":[{"list":"scientific-calculation","list_name":"scientific calculation","list_status":"active","list_url":"https://apptierlist.com/best/scientific-calculation/","position":7,"tier":"S","score":93.1,"components":{"rating":93.9,"votes":78.8,"rank":99.8,"recency":100},"status":"active","review_status":"checked","list_ranking_status":"ranked","confidence":"normal","judged_at":"2026-11-06T09:13:12.903Z"},{"list":"math-solving","list_name":"math solving","list_status":"active","list_url":"https://apptierlist.com/best/math-solving/","position":25,"tier":"C","score":68.2,"components":{"rating":93.9,"votes":78.8,"rank":0,"recency":100},"status":"active","review_status":"checked","list_ranking_status":"ranked","confidence":"provisional","judged_at":"2026-11-06T09:13:12.903Z"}],"main_list":"scientific-calculation","claim":{"status":"none","verified":false,"site_url":null,"verified_via":null,"verified_domain":null},"maker":null,"history":[{"id":285608,"at":"2026-11-09T20:54:12.713Z","kind":"tier_changed","list":"scientific-calculation","app_store_id":1673640297,"app":"scientific-calculator-fx-991-1673640297","from":"C","to":"S","reason":"score 68.2 to 93.2","job":"rescore"},{"id":278640,"at":"2026-11-07T22:29:12.569Z","kind":"tier_changed","list":"math-solving","app_store_id":1673640297,"app":"scientific-calculator-fx-991-1673640297","from":"D","to":"C","reason":"score 64.5 to 68.2","job":"rescore"},{"id":272219,"at":"2026-11-06T09:24:12.778Z","kind":"tier_changed","list":"scientific-calculation","app_store_id":1673640297,"app":"scientific-calculator-fx-991-1673640297","from":null,"to":"C","reason":"score 64.5","job":"rescore"},{"id":272214,"at":"2026-11-06T09:24:12.778Z","kind":"tier_changed","list":"math-solving","app_store_id":1673640297,"app":"scientific-calculator-fx-991-1673640297","from":null,"to":"D","reason":"score 64.5","job":"rescore"},{"id":272177,"at":"2026-11-06T09:13:12.903Z","kind":"membership_added","list":"scientific-calculation","app_store_id":1673640297,"app":"scientific-calculator-fx-991-1673640297","from":null,"to":"active","reason":"Built and marketed as a Casio fx-991 inspired scientific calculator with trigonometry, derivatives, integrals, and fractions.","job":"shadow"},{"id":272176,"at":"2026-11-06T09:13:12.903Z","kind":"membership_added","list":"math-solving","app_store_id":1673640297,"app":"scientific-calculator-fx-991-1673640297","from":null,"to":"active","reason":"Its step-by-step equation solver takes typed equations and returns detailed solutions, which is a headline feature.","job":"shadow"},{"id":272070,"at":"2026-11-06T08:36:13.040Z","kind":"app_added","list":null,"app_store_id":1673640297,"app":"scientific-calculator-fx-991-1673640297","from":null,"to":null,"reason":"discovered","job":"listTurn"}],"explain":{"method":"Membership is decided by a model judging the App Store listing against the list's definition (and its excludes, for memberships placed or rechecked since they were added to the prompt); every verdict is listed with its date; the score is an average of the components an app has (four public App Store signals, plus Apple's Editors' Choice badge as 100 where shown, plus ownership as 100 where the maker has verified it with our badge: it shows in components as ownership_verified); nothing is purchasable. 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