Going to have to try Waze - I keep hearing about it.
Currently use Houston Transtar's traffic map as my first-glance planner.
(
http://houstontranstar.org )
Google Maps will try to guide you around disasters, to some extent, but their maps may be two years out of date.
Even though I have an iPhone, I almost never use Apple's Maps.app.
There are several Vortices of Stupidity around the city that I regularly encounter. It helps to know where and when they form, and which lane is the most likely to get you there soonest.
All of the Vortices of Stupidity are caused by multiple merges, in a city where it seems like 75% of the drivers have no clue how to match velocity with the traffic in the next lane to squeeze into a hole, while not causing a wreck in either lane.
What I call Vortex of Stupidity #1 is southbound on I-45, between the South Loop and the three exits for Hobby (Broadway, Airport, and Monroe). There are cars entering from ramps on both the left and the right (in addition to the three through lanes from Downtown), and some of the people entering on the left are trying to exit at Broadway, and have to work across 5 or 6 lanes to get there.
The cars entering on the right are immediately in a this-lane-must-exit situation, and have to work towards the left, if they want to continue south.
My VoS#2 is also the Gulf Freeway, between the South Sam Houston Tollway, and (now) about FM2351, although the length varies.
Three through lanes, joined by the entering cars from both directions on the Belt, the HOV lane (in the evening), plus frontage road onramps, and a right-lane-must-exit at Scarsdale, compounded by construction shifts as they widen the entire thing to 379 lanes (jk).
VoS#.5 should probably be the exit from the South Loop eastbound onto the Gulf Freeway, and you are either in the right lane about a mile ahead of the exit, or you're trying to squeeze into the waiting line, while cars entering from the frontage road are competing on the other side of the line.
VoS#3 - 59 "north"bound between Hazard and 288. Two left lanes must exit to Spur 527. Right lane must exit (to Main St). Entrance lane from Shepherd vanishes, squeezing cars left. This and #.5 are the two that I always expect to be jammed, at any time of day.
VoS#4 - 59 @ the West Loop - this plugs up in all four directions, even after they created laced ramps. Imagine what it will be like when they replace the entire interchange during the next few years.
VoS#5 - 290 - ya know... just find another way to go...
"YMMV" - my knowledge of the VoSs is based on my driving patterns.
Add to the list, if you'd like.