I recommend browsing videos from Squat University on Instagram and seeing if you can identify the specific type and cause of knee pain and rehabbing that before you write it off as "part of aging".

I've had to resort to multiple apps and they don't work GREAT even when combined. I was just complaining about this!

I have Auto Photo Cut Paste for cutting faces/other parts out of photos fairly cleanly, and Picsart for actually combining/putting it together, but the Picsart tools seem kind of limited. It's not a full Photoshop replacement.

if it gives you an idea of what's possible. Face removed for anonymity.

the 500 comment limit made the concept of daily threads replacing common questions a killer on subs like r/fitness. "Has this question been asked before? Well, instead of being able to pull up several threads about this topic, I have to go through the daily threads of hundreds of days and search the comments for keywords - after increasing the number of comments visible from 200 to 500, and then still not being able to search all the comments on the 1000+ comment threads." Just genuinely became unusable.