Katawa Shoujo was over-rated. Its good, but not the "zOMG Mah Feels" the internet seems to think of it like gods gift to Weaboo. I should know, I'm a Weaboo through and through. I got a card and everything. Despite that, I'm adding a recommendation for it as well. It is definitely worth a read. Just be warned it contains explicit sexual content. very explicit sexual content. One of the project leads was an Aussie. Auto points for it there! Aussie Aussie Aussie!
I didn't see RenPy mentioned when I skimmed the thread. Apologies if it was already. There is a gajillion ones to chose from on there. All (or, most) run straight from the RenPy app. You can also make your own. That is what RenPy is all about really. As you would expect the stuff available there raned from the cringworthy bad stick figure "I want my 5 minutes back" variety to some seriously high quality hidden gems.
Wanted to make my own for years. None of my artist mates were interested in drawing for it, and none of my writer mates were interested in co-authoring one, soo.. boo hoo for me.
ok, editing is breaking URL tags. Sorry for that. Its getting worse every time I try. :(
Related and worth at least a skim. its a.. behind the scenes thing, literally.