Hi Ahmed -
First of all, i’m not very qualified to answer the question, as I haven’t even logged on to a developer account before… but i’m certainly willing to give my (lay) two cents on this:
I guess in my head I separate out the ‘legal’ protection from the ‘practical’ protection.
legally you can own the IP, but that would only likely protect you (I’m guessing) to the extent that you’d be willing to make a legal claim in his country/territory.
To suitably protect yourself legally, my guess is that you would need some sort of signed agreement from him stating that all Intellectual Property that he has created whilst working alongside / for you in respect of is owned fully and exclusively by you and revoking any IP claim he may have over it . Obviously though, that might be a touch difficult/awkward to create such an agreement and have him formally sign it, so maybe a second (less secure) level would be to obtain various emails/written text stating that it was ‘your’ app all his work was for, and that he was just a paid consultant (rather than a co-collaborator or co-creator).
But the thing is: that might protect you legally, but practically speaking, say he decides to steal your login, and take all the data… it would be quite a hassle for you (i’m assuming you’re not based in India) to launch a legal claim on it all whilst in a completely different country/territory. Having said that, perhaps (i’m reeeaaally guessing here) MAAAYBE apple might have their own App Store IP disputes process for things like this, whereby you might be able to submit any evidence (as the above) to Apple to get them to block ‘his’ app, without having to go through a legal court.
On a ‘practical’ protection level though, I imagine even if you change your ID/password etc to secure all your logins (to protect against the worst case scenario), it doesn’t give too much protection from him simply copying the files he has and launch them under his own login (maybe?).
But the above is all the doom and gloom bit… I’d guess that: if he builds apps for others as a living, then he would be majorly shooting himself in the foot should he turn around and ‘steal’ your data, as you’d doubtless sing from the mountain tops that he can’t be trusted, which would give him a bad reputation = loss of business, so you could take comfort in that (soft) protection.
…plus, you said he’s a trustworthy guy, so hopefully things will all be fine.
but to protect yourself legally i would keep all his invoices for his work, written evidence that he was creating this for you, and perhaps ask him to send you an email one day (if you think it’s fitting) to state that all IP for the app belongs to you.
The above is my two cents… but again, i’m kind of stabbing in the dark a bit here as i’ve never launched an app, so please forgive me if anything isn’t relevant… i just saw your message and thought i’d share my humble (lay) thoughts