Typed up version, summarized the most important bits. You can include this in the OP if you like, since I find it annoying to read images.
Damage Up: Increases damage of your main, sub and special weapons.
Damage Up increases the damage of main, sub, and special weapons up to 130%. However, weapons cannot pass their innate "number of hits to splat" threshold. For example, Aerospray MG has a base damage of 24.5, meaning that it takes five shots to splat at base; it cannot drop below this number, so Damage Up will cap its damage at 24.9, so it still takes five shots to splat. Damage Up is most useful when using weapons with a high rate of fire or those on the lower threshold of their number of hits to splat." This is ideal for countering opponents equipped with Defense Up.
Supplemental reading: Link.
Defense Up: Reduces damage taken from all attacks.
This ability reduces damage taken from all direct attacks up to 120%. Unlike Damage Up, it can lower thresholds on enemy weapons. For example, the .52 Gal does 52 base damage, making it a three-shot splat with the .52 Gal. This is one of the most valuable abilities, particularly if you're new to the game, decreasing the effectiveness of your opponent's weapons. Players with an aggressive play style also benefit from Defense Up.
Ink Saver (Main): Decreases the amount of ink consumed by your main weapon.
Ink Saver (Main) decreases ink usage of your main weapon by up to 60% of its normal usage. For example, a weapon that normally can continuously fire for 17 seconds becomes able to fire for just more than 27 seconds.
Ink Recovery Up: Increases ink tank refill rate while in squid form.
Ink Recovery Up increases your ink tank's refill rate by up to 40%, but only while in squid form--and you don't need to be swimming to gain this benefit.
Run Speed Up: Increases movement speed while in inkling form.
Run Speed Up increases your movement speed by up to 50% when in inkling form. This affects movement while running and while firing your weapon. However, it does not affect rolling speed with roller type weapons.
Quick Super Jump: Your Super Jumps are faster.
Quick Super Jump increases your Super Jump speed by up to double the normal rate, allowing for quicker deployment when jumping to teammates or Squid Beakons.
Bomb Range Up: Bombs, Point Sensors, and Disruptors travel farther when thrown.
This ability allows you to throw Splat Bombs, Burst Bombs, Suction Bombs, Point Sensors, and Disruptors up to 50% farther. The visible arc shown when tossing these weapons is noticeably extended, allowing you to toss these weapons impressive distances.
Opening Gambit: Boosts your speed in both Inkling and squid form for the first 30 seconds of battle.
Opening Gambit increases the Run Speed Up and Swim Speed Up parameters for the first 30 seconds of the match, allowing you to move much faster. This ability is restricted to headgear as a main ability.
Last-Ditch Effort: Boosts ink recovery rate and weapon ink efficiency for the last 30 seconds of the match.
This ability gives you a significant boost during the final seconds of each match, increasing Ink Saver (Main), Ink Saver (Sub), and Ink Recovery Up parameters. This ability is restricted to headgear as a main ability.
Tenacity:
Fills special gauge automatically if your team has fewer active players than the enemy. Tenacity fills your special gauge automatically if your team has more inactive players than the enemy team. A player is flagged as inactive while waiting to respawn--inactive players are shown at the top of the screen, represented by squids with X shapes over their eyes. The more inactive players your team has in comparison to the opposing team, the faster your special gauge fills. This ability is restricted to headgear as a main ability.
Recon: You can see the opposing team on the map while standing on the start point.
Recon allows you (but not your team members) to see the opposing team on the Gamepad's map while you're standing on your team's spawn point. This ability is restricted to clothing as a main ability.
Bomb Sniffer: Traps and hidden bombs set by your opponents are visible.
This ability is restricted to shoes and allows you to see Ink Mines that are hidden by opponents. All bombs (including Ink Mines) within a certain distance appear as skull icons on your screen. These skull icons can be seen through walls, so you can tell if opponents are throwing bombs around a corner at you.
Ink Resistance Up: Damage and movement penalties incurrend when moving through enemy ink are reduced.
Normally, you take 50 damage over three seconds while standing in enemy ink. Your movement speed is reduced to 12.5% of normal and you suffer a 60% reduction in jump speed and height as well. Ink Resistance Up changes all of this. When equipped, you only take a maximum of 25 damage when standing in enemy ink for six seconds. Your movement speed is reduced to 80% of normal and your jump speed and height are unaffected. This is clearly one of the most effective abilities thanks in large part to the reduction in the mobility penalties applied when moving through enemy ink. This ability is restricted to shoes as a main ability.
Stealth Jump: Your Super Jump landing points are hidden, but your Super Jumps are slower.
Normally when performing a Super Jump, a marker appears on the ground where you're about to land, which is visible to all players, including opponents. Stealth Jump hides the landing point marker. Your Super Jump speed is slightly reduced, but the decrease is negligible. This ability is restricted to shoes as a main ability.
Swim Speed Up: Increases movement speed while in squid form.
This ability increases squid form movement by up to 25%, also while using the Kraken special.
Special Charge Up: Increases special-gauge fill rate.
Special Charge Up increases the rate of which the special gauge fills by up to 30%.
Special Duration Up: Increases usage time of special weapons.
Increases duration of special weapons: Bubbler, Inkzooka, Kraken, Bomb Rush, Echolocater all last longer. Inkstrike and Killer Wail are given more time to aim the weapons. Increased Bubbler duration is also passed to teammates, regardless if they have Special Duration Up.
Quick Respawn: Decreases respawn time after getting splatted.
Decreases time watching the splat cam by up to 66% after getting splatted. Splat cam normally lasts 6 seconds, while the respawn animation lasts 3, for a total of 9 seconds. Quick Respawn only effects the splat cam portion. Fully stacked (three Quick Respawn abilities) the splat cam is reduced to 2 seconds, for a total of a 5 second respawn time.
Special Saver: Reduces the amount your special gauge decreases after getting splatted.
This ability reduces special charge loss after a splat by up to 100%. Normally, you lose 50% of your gauge upon death.