Shape-pa is a peer to peer sharing website that tries to connect like minded people that want to simply share things. The site is not for renting but for sharing. It is free of cost and not meant for commercial purposes.
As a first step you can check their profile for its authenticity. Trustworthy Share-Pa user would generally have more positive reviews than negative. You should also go through their testimonials to see what others have to say about them. Also you’ll notice that some of the active Share-Pa members would also have badges that honor them for their commitment. Also check if the user is part of your ‘circle of trust’ through common people you know or communities you are members of.

Beside this, you can always chat with other users using our messaging feature to get to know each other or to get their phone numbers. We also recommend that you meet the borrower or lender in-person for exchange of the items, so that you can get to know them well.
If you are a borrower, it goes without saying that you should be careful when using the borrowed items. In case of the damage/ loss of an item, we recommend you recompense the lender either in cash or kind.

If your lent item is stolen/ lost/ damaged there are multiple actions you can take. You can deduct the deposit charged partially/ completely. You can give a negative review and testimonial to the borrower, so that other users are cautious when dealing with them. For a high value item, we recommend you add the serial number of the item while posting it, so that you have it on record. 
However, Share-Pa.com and/or its management do not take any liability or responsibility for the damage caused to an item in the sharing process.
No, currently Share-pa does not have an app, but might think of developing one in future depending upon the demand.