I've installed this app a long time ago. Share it is an app which is used to share the media with other devices. There are many apps which are used to share the media like ES File explorer, Files Go etc., at present. Previously, there was file transfer only via Bluetooth. Even if you want to transfer via MMS you can't send large media and it even costs you.
But coming to share it the file transfer is so simple. Just switch on share it, the receivers device hotspot get turned on and senders WiFi. Vice versa with I phone.
You can transfer audio, video, images, folders, documents.
But, the share it version got updated frequently. Currently, you can view videos from YouTube. There was no separate option to play and display the files. But now You can play your files separately.
Even there's a junk cleaner inside the app which deletes the unwanted files like clean master. It informs the sender and receiver if there is problem in the device like storage problem etc.,
But, many times it says to upgrade the app when opened. It is different from play store update. If you didn't so that it always pops that and you get annoyed.
Rest everything nice. Many apps use this technique to share the media.
Now a days Share it became a default app by every mobile.
I recommend you to install this.
Thank You.