Although not a UI, @paulag has been offering a small incentive to power-up for a year now, and with the help of @yabapmatt, @steemcommunity for 39 weeks.

https://steemit.com/steem/@paulag/announcing-the-wolfhart-wall-of-fame-celebrating-1-year-of-the-redfish-power-up-league

https://steemit.com/community/@steemcommunity/the-minnow-power-up-league-week-39

Encouraging and intensifying this action can only lead to good things!