Even though it only has four strings compared to the guitars six, you'll still get a fairly full sounding chord from a ukulele. What's more is that after learning a bunch of chords on the uke and playing songs, you'll become familiar with playing notes on a fret board, strumming, chord structures, etc. All of which transfer rather nicely to playing guitar.
I struggled with learning to play guitar for a long time and knew that there was something I wasn't getting. Since the chords were so much easier to play on the ukulele, I got good at playing them quickly. This turned out to have a snowball effect on learning songs, chord progressions, etc. When I picked up my guitar again some weeks later, I knew the chords to a bunch of new songs from playing them on the ukulele. This encouraged me to buckle down and finally master the open chords on guitar.
If you've been struggling with guitar or want something to ease you into it, pick up a ukulele and learn some chords. Here are a few easy video lessons to get you started: