This is a tiny feature request, but it would be great if I could search for ‘aim’ in the app, or even filter to all pennystocks (including non-UK).
You could search here for now or in the stock universe spreadsheet although I don’t think AIM stocks are tagged in the spreadsheet.
This has been suggested before. Please vote on that idea.
It was obviously quite a while back, but the 
team do read the forum. It’s likely on a long, long to-do list and isn’t a high priority for them.