Life In 19x19

I am looking for recommendations from go players for a go problems (tsumego) application on Android.

Some context:
Until recently, I was using Wbaduk who had a "Problems" sections and was very happy with it. Even though the interface was lacking and some problems were bugged, the collection was large, difficulty levels were very accurate, there were few errors in the problems and many problems were surprising and hard to find anywhere else. Unfortunately, it no longer works for me since the last update.

I also use Tsumego Pro but I like it less and less: even with a better interface, the set of problems is smaller (even with a few optional sets) and feel more classical and repetitive.

This was just to give you an idea of my priorities. I am looking for opinions about alternatives.
- I am roughly 1k-1d.
- I am ready to pay (but there are too many paying applications to try them all)
- Language doesn't matter (in fact I suspect there might be some hidden korean/chinese gems)

Thank you by advance.

Alternatively, if you know an application that takes problems is sgf format and gives you a problem-like interface, I would be interested as well.

GoGrinder is a great app/program (Android version available) for problems if you have a collection of sgf problems. - It's probably the app I use most for this.

If you don't mind paying, pandanet has a great life and death program.
https://play.google.com/store/apps/deta ... et.tsumego

That pandanet tsumego app is nice but so expensive as you need to keep paying to keep having the premium mode.
The tsumego solving function reminds me of the GoTools MSDOS proggy but you only need to pay once for that.

For paid tsumego go problems for Android I recommend Tsumego Pro.

sahwal.com

They also provide an android app, which I'm using.

Thank you all for your suggestions.

Paying every month for Pandanet premium is a bit too much just to get access to problems, but we'll see.
I bought two sets of problems from Tsumego Pro and I will not buy another one unless I have some guarantee they are of a better quality (although this is of course very subjective).

I will try sahwal.com and some other at random and give my thoughts here.

Pandanet doesn't require paying monthly. I just pay for sets of problems.

Thanks again for your suggestions. I ended up using GoGrinder. Although it lacks a few features I would like, it is very clean and I appreciate the flexibility to get my own sgf problems. Now my main problem has become to find classical collections in sgf format.

I found the sahwal program pretty good but the fact that it did not work without a connection was a deal breaker for me. I had the same problem with Panda-Tetsuki and many other programs. I have tried a variety of other programs but I do not feel any of them deserves any particular mention.