this app requires specific features not available on this device

H2018 wrote:

nothing is banned in Egypt, and everything works in the US using my roaming sim card

Then what is the problem?

Phones who's model ends in AE, generally are meant for regions where Facetime is banned or restricted.

If it was a phone mean for Egypt, Apple clearly states it may not have Facetime outside of Egypt or its carriers.

Egypt restricts Facetime, and last year banned VOIP services all together,

Wireless carrier support and features for iPhone in Africa - Apple Support

FaceTime might be unavailable if your device originates from Egypt and becomes unlocked or is used in another country or region.

http://identity-mag.com/egypts-government-shuts-voip-like-skype-facetime-fb-mess enger/

If it is unlocked the iPhone will work, but yes there are limitations to what it can do if it comes from a country where certain things are banned.

Just because its unlocked does not mean it can magically bypass the restrictions of the region it was meant for.

If it was meant for a region that bans Facetime or restricts it to certain carriers only then it won't have Facetime outside of the region or the specific carriers.

Unless you require Facetime, you can use the iPhone normally. If you do require Facetime and cannot live without it, then yes, you need a new phone from a region where Facetime is not banned or restricted.

Why do you think you would need to do that?

No...why should you? Unless it is carrier locked. Is it? if it is get it unlocked by your carrier.

PS the iPad should not be carrier locked.

Only the original cellular provider can unlock your iPhone. Contact them to determine their unlocking policy, and if you qualify.

Understood, there is no way to change that, but if it isn't locked, you should be able to use it on the AT&T network.

Now you are being clear(er). FT will not work on that phone.

You missed the point: Some phones sold in the Middle East have FT crippled because of local law.