Ability Wristbands would be the addition of items that change things in game, such as the rate in which specific items are acquired. The wristbands are items earned through the completion of challenges or the possession of medals and other things. Each Wristband is different, and when worn it gives a unique ability. The player can have a max of two wristbands to be on at any given time. Of course, all the ideas said here aren't exact and could always be changed. Here are some examples for Wristbands, how they are acquired, and the effects they give off.
The Dusty Wristband : Increases the rate of stardust earned by 25% ::: Earned once 300k Stardust is used on Pokemon
The Buddy Wristband : Decreases distance needed to travel for each buddy candy by 25% ::: Earned when player has the silver "Jogger" medal and has walked at least 50 km with one single buddy
The Clover Wristband : Increases chances of getting an Evolution Item from a normal Pokestop spin, increases chances of receiving TM's from raids, increases chances of receiving candy from feeding berries in gyms, and occasionally gives the player one extra candy from a caught Pokemon. ::: Is earned from owning a silver "Berry Master" medal and a bronze "Champion" medal. (Raids)
The Gym Membership Wristband : Increases gym badge xp earnings by 100%, each Pokemon defeated by player loses 10% more motivation, the player's defending Pokemon loses 10% less motivation, coins are earned 10% faster and maxcoin limit per day becomes 60, and there is a 50% chance of receiving an extra item from spinning a gym picture. ::: Earned when the player has won 500 gym battles and owns 3 silver gym badges.
The Raider Wristband : Increases items earned from a raid by 15%, and a player can hold two daily raid passes at a time.(still earns one a day) ::: Earned by having a silver "Champion" medal.
When putting on a wristband or switching one out, the player must walk 5 km to "charge up" the wristbands before any effects occur. This prevents someone from just putting on a Raider Wristband and a Clover Wristband before a raid to receive optimum rewards, then switching it right off the second after. Any other ideas for wristbands or any changes necessary to the ones I have suggested? Also, please don't comment something like "but but I don't have 3 gyms in my super rural town! I can't get three silver gym badges to get a Gym Membership Wristband! This can't happen!" because this is just an idea and can be changed. Thanks for any positive additive ideas!