All great insights on this thread. I had one thought. If you're looking to join an accelerator, most will reject you if you do not have a CTO Co-founder or technical employee that would be joining you (if you don't have any traction). If you can get into an Accelerator that will fund you without taking excessive equity, maybe you can try to.
If you want to go to market right away, skipping any BETA testing, likewise, it's best to hire someone if you can. If your app is B2B. bigger clients will want to see that you have in-house developers, even if the team is distributed (Like Groove), https://www.groovehq.com/blog/being-a-remote-team
....and that you are NOT outsourcing.
If its a consumer APP,and you are not seeking additional funding and not trying to join any accelerators, this might not matter as much. So as others have said, hire the best outsourcing team possible with your budget and or since your team has already built the product, they're already most familiar with the code so you can stick with them and add team technical team members as needed.