That is crazy,

it is a net engine.

I had one explode. It has turbine blades and blew up like a handgrade but it is a jet engine. It is just used differently than an APU but it is just about the same thing

The F-16 does have a provision to manually pump up the hydraulic accumulator to spin up the JFS if there's insufficient pressure in the hydraulic system to get the job done.
It's strenuous work, some say it's roughly equivalent to doing 150 or so pushups to manually pump the accumulator up to full charge.

A full charge is sufficient for two normal start attempts.  After that someone has to go find the pump handle inside the port wheel well, and start pumping.

The system recharges automatically when the engine is operating.  But if you attempt two engine starts and fail to light off the engine correctly, you're going to get some exercise.

I could not find the information on exactly how many times you have to pump the handle in order to recharge the accumulator.  But it's enough that you really don't want to blow the start sequence.

^ yep.

Auxiliary power unit meaning you can use it as another powersource with engines off without having to resort to something like a hobart or -60 and being able to run for hours.

JFS run time is in minutes and used for starting/motoring only. Need power? Get AGE.

I never said it wasn't a turbine.

I have seen them catch on fire when the fuel manifold that sits above it shit the bed.  Damn near burned up the jet.  It was the only time I used a Halon bottle and I used 2 on that bitch.  The fire was right by the single point for where we refuel the F16.

Good explanation.  On different 135 models most have APUs but a few have JFSs.