Any recommendations of people or resources are welcome
I'm happy to try and assist.
Send me more details about the type of help you're looking for, about the app, the target market + the current status of the app/business, and I'll be happy to try and help. If I can give you some free advice by email I'll be happy to do so. If you'll need more help we can schedule a call.
As for tool, here's a whole bunch of tools and resources from Steve Blank (the man behind the Lean Strategy): https://steveblank.com/tools-and-blogs-for-entrepreneurs/
Best of luck