Hello Sean
For MCUXpresso see the following: https://community.nxp.com/thread/474390
Also take a look at http://www.utasker.com/kinetis/FRDM-KL28Z.html
The uTasker KL28 project includes complete projects for most IDEs:
NXP's MCUXpresso
NXP's Kinetis Design Studio (KDS)
Freescale's CodeWarrior 10.x
S32 Design Studio for ARM
Rowley Associate's Crossworks
CooCox CoIDE
IAR Embedded Workbench
Keil µVision
Green Hills
Atollic TrueSTUDIO for ARM
Standalone GCC from Makefile
VisualStudio for Kinetis simulation
and allows complete project simulation (including peripherals, interrupt, DMA etc.) and CGG make file building directly from Visual Studio.
Beware however that the KL28 presently has a lead time of about 40 weeks so you will may need to keep your options open if you need to produce fast turnaround developments.
"NXP = Freescale" so there is no general problem with Kinetis parts (NXP is, or will be, Qualcomm - and Broadcom is also biding on Qualcomm, so best close your eyes if stability is an input to your choice of silicon)
Regards
Mark
uTasker developer and supporter (+5'000 hours experience on +60 Kinetis derivatives in +80 product developments)
Kinetis: http://www.utasker.com/kinetis.html