CapnZapp
Legend
Friends - Rename it Frenemy and you're done... 
The problem isn't what the spell does, but that it doesn't do what the name implies it does. (Also see Barkskin)
True Strike - I have no problems with this being incredibly circumstantial. I certainly don't want this to become useful in regular combat. The problem is that in the case where it actually would be useful, that is an ambush, you are already gaining advantage. The spell needs to stack with surprise and attacking unseen, since otherwise it's confined to the ultra-special case where you need to do a Wilhelm Tell thing, and nobody minds you "cheating" by magically improving your chances.
Blade Ward - in essence, what it does is give you an option to the Dodge action. Instead of "resistance" to being hit, you have resistance to the actual damage. As such it isn't too shabby. Guess your point is that Dodge is often enough, so nobody takes this cantrip? All in all, as a problematic spell I'd place it at low priority to fix. It's not outright broken - so what if it's not a commonly taken option?
Jump - definitely broken, since it doesn't actually increase the amount of space you can move in a round (as confirmed by Sage Advice). I dislike the fiddliness with referencing the jumping rules. It should give you something expressed as a proper speed in feet. For instance, make it give you a Jump Speed of 30. Which basically is flight with the restriction you must begin and end your round holding or standing on something. Or decrease the duration to a single round and let the spell give you +30 ft Speed for one round, all of which can be used for a "jump" in any direction.
Witch bolt. The way range breaks the spell needs to go. The way cover breaks the spell needs to go. Already the spell no longer is execrable. As long as the spell requires Concentration the spell can't end just because you miss your initial ranged spell attack. (Yes, the way the spell is written means that if your attack fails the spell doesn't do anything. It doesn't formally end, but a miss means you can't use the casting for anything, since you don't get a new try to make it "connect" to a target). The way you need to spend your action should probably stay. I suggest that the spell isn't tied to the initial target; that you can switch targets (because the first one died or fled) by making a new ranged spell attack as part of your witchbolting action. That way, you CAN switch, but at the risk of failing (and thus wasting your action).
I was tempted to remove the word "initial" from the At Higher Levels section, but reconsidered. My job here is done, the spell is now usable. No need to go overboard...
Since that became messy, here's a complete revised write-up:
W i t c h B o l t
1st-level evocation
Casting Time: 1 action
Range: 30 feet
Components: V, S, M (a twig from a tree that has been struck by lightning)
Duration: Concentration, up to 1 minute
You form a beam of crackling, blue energy between your outstretched hands. Make a ranged spell attack towards a target within range. On a hit, the target takes 1d12 lightning damage. On a miss, you still retain the beam. On each of your subsequent turns for the duration, you can use your action to make a new ranged spell attack against a target. If you attack the same target your Witch Bolt dealt damage to in the immediately previous turn, the target is hit automatically. The spell ends if you use your action to do anything else.
At Higher Levels: When you cast this spell using a spell slot of 2nd level or higher, the initial damage increases by 1d12 for each slot level above 1st.
The problem isn't what the spell does, but that it doesn't do what the name implies it does. (Also see Barkskin)True Strike - I have no problems with this being incredibly circumstantial. I certainly don't want this to become useful in regular combat. The problem is that in the case where it actually would be useful, that is an ambush, you are already gaining advantage. The spell needs to stack with surprise and attacking unseen, since otherwise it's confined to the ultra-special case where you need to do a Wilhelm Tell thing, and nobody minds you "cheating" by magically improving your chances.
Blade Ward - in essence, what it does is give you an option to the Dodge action. Instead of "resistance" to being hit, you have resistance to the actual damage. As such it isn't too shabby. Guess your point is that Dodge is often enough, so nobody takes this cantrip? All in all, as a problematic spell I'd place it at low priority to fix. It's not outright broken - so what if it's not a commonly taken option?
Jump - definitely broken, since it doesn't actually increase the amount of space you can move in a round (as confirmed by Sage Advice). I dislike the fiddliness with referencing the jumping rules. It should give you something expressed as a proper speed in feet. For instance, make it give you a Jump Speed of 30. Which basically is flight with the restriction you must begin and end your round holding or standing on something. Or decrease the duration to a single round and let the spell give you +30 ft Speed for one round, all of which can be used for a "jump" in any direction.
Witch bolt. The way range breaks the spell needs to go. The way cover breaks the spell needs to go. Already the spell no longer is execrable. As long as the spell requires Concentration the spell can't end just because you miss your initial ranged spell attack. (Yes, the way the spell is written means that if your attack fails the spell doesn't do anything. It doesn't formally end, but a miss means you can't use the casting for anything, since you don't get a new try to make it "connect" to a target). The way you need to spend your action should probably stay. I suggest that the spell isn't tied to the initial target; that you can switch targets (because the first one died or fled) by making a new ranged spell attack as part of your witchbolting action. That way, you CAN switch, but at the risk of failing (and thus wasting your action).
I was tempted to remove the word "initial" from the At Higher Levels section, but reconsidered. My job here is done, the spell is now usable. No need to go overboard...
Since that became messy, here's a complete revised write-up:
W i t c h B o l t
1st-level evocation
Casting Time: 1 action
Range: 30 feet
Components: V, S, M (a twig from a tree that has been struck by lightning)
Duration: Concentration, up to 1 minute
You form a beam of crackling, blue energy between your outstretched hands. Make a ranged spell attack towards a target within range. On a hit, the target takes 1d12 lightning damage. On a miss, you still retain the beam. On each of your subsequent turns for the duration, you can use your action to make a new ranged spell attack against a target. If you attack the same target your Witch Bolt dealt damage to in the immediately previous turn, the target is hit automatically. The spell ends if you use your action to do anything else.
At Higher Levels: When you cast this spell using a spell slot of 2nd level or higher, the initial damage increases by 1d12 for each slot level above 1st.
