DEV APP IOS/ANDROID

I would like to offer you my project. It should be an App like Kipy ( https://kipy-it.translate.goog/?_x_tr_sl=it&_x_tr_tl=en&_x_tr_hl=it&_x_tr_pto=wapp ) but the documents need to be certified on blockchain. I fixed a budget but we can discuss it. Thanxs