What is the best alternative to Sing Sharp - Singing Lessons on iPhone?

Simply Sing: My Singing App, S tier, #1 in voice coaching.

Is there a free alternative to Sing Sharp - Singing Lessons?

Yes: Simply Sing: My Singing App (S tier, #1) is free to download, with in-app purchases.

Yes. 2 apps rank above it in voice coaching: Simply Sing: My Singing App (#1), Vocalista: Learn to Sing (#2).

Sing Sharp - Singing Lessons is A tier, #3 of 7 in voice coaching. Here is everything that competes with it on iPhone, in tier order.

1
Simply Sing: My Singing AppShigher tier
Free + IAP · ★ 4.7 · 460,586 ratings · score 98
Singing app that finds your voice type, adjusts songs to your voice, and gives feedback on your singing.
2
Vocalista: Learn to SingShigher tier
Free download · ★ 4.6 · 3,289 ratings · score 91
A free iOS app with vocal exercises adjusted to your range, real-time pitch feedback, and short singing theory lessons.
4
Vocalist: Learn to SingA
Free download · ★ 4.8 · 1,847 ratings · score 86
Free education app offering singing warm-ups, song practice, video lessons and real-time feedback on notes and breath.
5
Vocal Range Finder - Sing WhizA
Free download · ★ 4.4 · 2,969 ratings · score 86
Measures your vocal range, offers singing exercises, and finds artists whose vocal ranges match yours.
6
Erol Singer's StudioC
Free + IAP · ★ 4.8 · 3,411 ratings · score 67
Voice training app with singing lessons in progressive levels and pitch tracking, free to download.
7
Learn to Sing - Perfect PitchC
Free download · ★ 4.4 · 15,997 ratings · score 63
Singing practice app that shows real-time pitch accuracy, with vocal warm-ups, sing-along songs and a 10-level training.

What is the best alternative to Sing Sharp - Singing Lessons on iPhone?: Simply Sing: My Singing App, S tier, #1 in voice coaching.
Is there a free alternative to Sing Sharp - Singing Lessons?: Yes: Simply Sing: My Singing App (S tier, #1) is free to download, with in-app purchases.
Does anything rank above Sing Sharp - Singing Lessons?: Yes. 2 apps rank above it in voice coaching: Simply Sing: My Singing App (#1), Vocalista: Learn to Sing (#2).