Thanks for checking it out - really appreciate the feedback. Some responses:

"the web version costs money after 90 days but the app is free. Why the differences?"

Because the web version stores your data on my server (and thus making it syncable to all your devices) - and so for that capability (and to cover my server operational costs), it's a paid feature. But if just using the iOS app, all of your data is by default stored locally on the device (I'm using Sqlite for that), and so that's free (since I don't incur any operational costs for that).

"it seems that I cannot add any other exercises apart from the ones provided, would be nice to be able to quickly log what I wanna do."

I thought about that in the beginning, and ultimately decided against it for simplicity; and would instead go the route of incrementally adding more and more exercises myself to the app. But will perhaps re-think this.

"the records list view on mobile is a bit squished (i.e. I find it difficult to horizontally scroll)"

Will look into this. I'm currently using an OSS library for the records display, and so I'll see if there are params I can tweak.

"no support for super-sets: I do a lot of circuit training and I somehow managed to add this feature to Ewolo using a rest parameter. I'm still not sure what the best way to model this data would be without making it cumbersome."

I also struggle with how to model supersets - more so from a UX standpoint. You're totally right - you'd think a rep tracker would be easy, but as you get into it, there's quite a bit of complexity that emerges. I think I have a good way to handle supersets, but that will have to be for a future release...currently trying to get the Android app (and Gear app) done.

Thanks again for the comments.

[edit - typos etc]