What is the best alternative to memoryOS: Memory Games on iPhone?

NeuroNation - Brain Training, S tier, #2 in memory training.

Is there a free alternative to memoryOS: Memory Games?

Yes: NeuroNation - Brain Training (S tier, #2) is free to download.

No. memoryOS: Memory Games is #1 in memory training.

memoryOS: Memory Games is S tier, #1 of 6 in memory training. Here is everything that competes with it on iPhone, in tier order.

2
NeuroNation - Brain TrainingS
Free download · ★ 4.7 · 4,502 ratings · score 92
Brain training app with puzzles, memory and speed games, and logic challenges that adjust to your performance.
3
BrainHQA
Free + IAP · ★ 4.6 · 21,963 ratings · score 89
Brain training app with adaptive exercises for memory, attention, processing speed and perception, from Posit Science.
4
Train Your Brain: Memory GamesA
Free + IAP · ★ 4.6 · 5,804 ratings · score 89
Free memory training app with card pair, sequence, path and pattern games across multiple levels, with score tracking.
5
Memorize By HeartC
Free download · ★ 4.8 · 2,454 ratings · score 67
Memory training app that helps users memorize speeches, poems, scripts, lyrics and study material through practice.
6
Brain Puzzle Games for AdultsC
Free + IAP · ★ 4.3 · 17,624 ratings · score 60
Daily brain games that test short-term memory and give a brain age estimate without showing an exact age.

What is the best alternative to memoryOS: Memory Games on iPhone?: NeuroNation - Brain Training, S tier, #2 in memory training.
Is there a free alternative to memoryOS: Memory Games?: Yes: NeuroNation - Brain Training (S tier, #2) is free to download.
Does anything rank above memoryOS: Memory Games?: No. memoryOS: Memory Games is #1 in memory training.