The Mevo app gives you the option to add a default signature or hashtag to the end of stream's title.
Open the app's settings by tapping the 'More Options' icon, followed by the gearwheel.
Tap the 'General' menu.
Towards the bottom is an option for 'Signature.' Tap this to set a signature.
Type in your desired signature. If you wish for it to be a hashtag, be sure to include the hash symbol (#) in your signature.
When you go live, that signature will by default be added to the end of every stream title.