i didnt see this in the faq or anywhere else. I saw you can combine v1 and v2, but can i use the app with v1? trying to see if i can avoid rebuying whats mostly the same game

No - you can use first edition tiles, investigators and monsters with the second edition, but you cannot use the app, which will have all new scenarios, with the first edition.

The app can't be used with 1E, but the conversion kit will allow you to use the rooms, monsters, and investigators from 1E in your 2E games.

I've always found the idea of Mansions to be amazing, but as the lone "hardcore" gamer in a group of mostly casuals and significant others, the semi-coop nature makes it really hard to get to the table. Either I have to hold back a lot to keep from smoking the investigators as Keeper or I have to coach the Keeper on how best to kill us as an Investigator. So from that standpoint, I'm super excited to see a fully Coop version.

But...I hope the Conversion kit has some way to play the game in a Semi-Coop mode. It may not have worked out for my group but in the right hands it's a really fun back and forth.

It's all in how they do it. If they've tested it enough (and the app works fast and well) it could be great.