I don't that lost coins can be recovered. As of now, there is no app that will help you out. Those apps saying they can, most likely they are malwares designed to steal more of your coins. It's really hard to trust especially apps pretending to help you. Start checking your computer of malwares.
indeed there are many applications or software that promote that they can return your lost coins but, don't be easily affected and true if they only want to cheat by stealing more coins that you have I am also sure the coins that have been lost will indeed be difficult to return to if you have lost it is better to ask for help from those who know better.