My best advice for the phone apps is try the free ones first, see if you like them or not. I have a few apps on my tablet, but I don't really use them since I've probably spent over $2000 on different types of equipment for investigating with. I need to get my monies worth out of them!
For the Spirit Box / Ouija Board comparison. I've heard the debate that they are the same thing and that they or not. IMHO, anything you use to communicate with Spirits is of the same camp. A different means to fufilling the same objective: contact.
Though I don't necessairly agree that using a Ouija board is akin to opening a portal into a dark place. That's more the intent of the person using the board, or any device for that matter. I agree 100% with what Teal said regarding its use.
Bottome line, if you feel uncomfortable taking part in any type of paranormal communication, then its best you don't do it until you're ready.