Let's list all the signing and reports of signings of the undrafted free agents. I will try to get some of the ones from the draft thread and post them here.
Lynden Trail http://www.nfl.com/draft/2015/profiles/lynden-trail?id=2552298 Jake Cotton http://espn.go.com/college-football/player/_/id/501845/jacob-cotton
Greg Mancz, G/C, Toledo Apparently a steal. Will probably make the team as a backup OL (taking Cody White's place).
<blockquote class="twitter-tweet" lang="en"><p lang="en" dir="ltr"><a href="https://twitter.com/hashtag/Texans?src=hash">#Texans</a> have signed Oregon's Tony Washington Jr. (OLB)</p>— PDS (@PatDStat) <a href="https://twitter.com/PatDStat/status/594641425523814400">May 2, 2015</a></blockquote> <script async src="//platform.twitter.com/widgets.js" charset="utf-8"></script>
<blockquote class="twitter-tweet" lang="en"><p lang="en" dir="ltr">Tony Washington OLB Oregon to <a href="https://twitter.com/hashtag/Texans?src=hash">#Texans</a> per media reports</p>— Mike Loyko (@NEPD_Loyko) <a href="https://twitter.com/NEPD_Loyko/status/594641660325318656">May 2, 2015</a></blockquote> <script async src="//platform.twitter.com/widgets.js" charset="utf-8"></script>
<blockquote class="twitter-tweet" lang="en"><p lang="en" dir="ltr"><a href="https://twitter.com/hashtag/Texans?src=hash">#Texans</a> sign DT Brandon Ivory from Alabama.</p>— PDS (@PatDStat) <a href="https://twitter.com/PatDStat/status/594641711046897664">May 2, 2015</a></blockquote> <script async src="//platform.twitter.com/widgets.js" charset="utf-8"></script>
<blockquote class="twitter-tweet" lang="en"><p lang="en" dir="ltr"><a href="https://twitter.com/hashtag/Texans?src=hash">#Texans</a> sign DE James Rouse from Marshall.</p>— PDS (@PatDStat) <a href="https://twitter.com/PatDStat/status/594642541259067392">May 2, 2015</a></blockquote> <script async src="//platform.twitter.com/widgets.js" charset="utf-8"></script>
<blockquote class="twitter-tweet" lang="en"><p lang="en" dir="ltr">Breaking: <a href="https://twitter.com/HoustonTexans">@HoustonTexans</a> sign PFA DE James Rouse Marshall <a href="https://twitter.com/FBallInsiders">@FBallInsiders</a></p>— College2Pro.com (@BoMarchionte) <a href="https://twitter.com/BoMarchionte/status/594642268515999744">May 2, 2015</a></blockquote> <script async src="//platform.twitter.com/widgets.js" charset="utf-8"></script> <blockquote class="twitter-tweet" lang="en"><p lang="en" dir="ltr"><a href="https://twitter.com/hashtag/Texans?src=hash">#Texans</a> sign DT Brandon Ivory from Alabama.</p>— PDS (@PatDStat) <a href="https://twitter.com/PatDStat/status/594641711046897664">May 2, 2015</a></blockquote> <script async src="//platform.twitter.com/widgets.js" charset="utf-8"></script>
<blockquote class="twitter-tweet" lang="en"><p lang="en" dir="ltr">Former Trojan Chandler Worthy has signed a priority undrafted free agent deal with the Houston Texans! <a href="http://t.co/xRiLxNczM0">pic.twitter.com/xRiLxNczM0</a></p>— Troy Athletics (@TroyAthletics) <a href="https://twitter.com/TroyAthletics/status/594643167967862784">May 2, 2015</a></blockquote> <script async src="//platform.twitter.com/widgets.js" charset="utf-8"></script>
<blockquote class="twitter-tweet" lang="en"><p lang="en" dir="ltr">Troy WR Chandler Worthy has signed with the <a href="https://twitter.com/hashtag/Texans?src=hash">#Texans</a></p>— PDS (@PatDStat) <a href="https://twitter.com/PatDStat/status/594643516329840640">May 2, 2015</a></blockquote> <script async src="//platform.twitter.com/widgets.js" charset="utf-8"></script>
<blockquote class="twitter-tweet" lang="en"><p lang="en" dir="ltr">Dan Pettinato has found a home with the Houston Texans. He's the 4th Wildcat to sign a free agent deal since draft ended.</p>— Daniel Berk (@DSBerk) <a href="https://twitter.com/DSBerk/status/594646087689900032">May 2, 2015</a></blockquote> <script async src="//platform.twitter.com/widgets.js" charset="utf-8"></script>
<blockquote class="twitter-tweet" lang="en"><p lang="en" dir="ltr">Appaclachian State OT, Kendall Lamm has signed with the <a href="https://twitter.com/hashtag/Texans?src=hash">#Texans</a> (Per <a href="https://twitter.com/DraftDiamonds">@DraftDiamonds</a>)</p>— PDS (@PatDStat) <a href="https://twitter.com/PatDStat/status/594646606349107200">May 2, 2015</a></blockquote> <script async src="//platform.twitter.com/widgets.js" charset="utf-8"></script> <blockquote class="twitter-tweet" lang="en"><p lang="en" dir="ltr">Former Louisiana Tech DE/LB Houston Bates is signing a deal with the Houston Texans. He'll start mini camp next Thursday <a href="https://twitter.com/LATechFB">@LATechFB</a></p>— Sean Isabella (@ST_IsabellaTNS) <a href="https://twitter.com/ST_IsabellaTNS/status/594646867507425281">May 2, 2015</a></blockquote> <script async src="//platform.twitter.com/widgets.js" charset="utf-8"></script>
<blockquote class="twitter-tweet" lang="en"><p lang="en" dir="ltr">Bowie State TE Khari Lee to the <a href="https://twitter.com/hashtag/Texans?src=hash">#Texans</a>.</p>— PDS (@PatDStat) <a href="https://twitter.com/PatDStat/status/594649128644153344">May 2, 2015</a></blockquote> <script async src="//platform.twitter.com/widgets.js" charset="utf-8"></script> <blockquote class="twitter-tweet" lang="en"><p lang="en" dir="ltr">Congrats to Will Johnson signing with the Houston Texans <a href="https://twitter.com/hashtag/EatEmUpBobcats?src=hash">#EatEmUpBobcats</a></p>— Coach Brad Bedell (@BradBedell) <a href="https://twitter.com/BradBedell/status/594650999668617217">May 2, 2015</a></blockquote> <script async src="//platform.twitter.com/widgets.js" charset="utf-8"></script>
<blockquote class="twitter-tweet" lang="en"><p lang="en" dir="ltr">Coastal Carolina Safety Quinn Backus signs with the <a href="https://twitter.com/hashtag/Texans?src=hash">#Texans</a></p>— PDS (@PatDStat) <a href="https://twitter.com/PatDStat/status/594651733789315072">May 2, 2015</a></blockquote> <script async src="//platform.twitter.com/widgets.js" charset="utf-8"></script> <blockquote class="twitter-tweet" lang="en"><p lang="en" dir="ltr"><a href="https://twitter.com/hashtag/Texans?src=hash">#Texans</a> sign Texas State Punter Will Johnson.</p>— PDS (@PatDStat) <a href="https://twitter.com/PatDStat/status/594651274982731776">May 2, 2015</a></blockquote> <script async src="//platform.twitter.com/widgets.js" charset="utf-8"></script>
<blockquote class="twitter-tweet" lang="en"><p lang="en" dir="ltr"><a href="https://twitter.com/hashtag/Texans?src=hash">#Texans</a> sign Henderson State QB Kevin Rodgers.</p>— PDS (@PatDStat) <a href="https://twitter.com/PatDStat/status/594650733217067009">May 2, 2015</a></blockquote> <script async src="//platform.twitter.com/widgets.js" charset="utf-8"></script>
<blockquote class="twitter-tweet" lang="en"><p lang="en" dir="ltr">Kurtis Drummond S Michigan State to <a href="https://twitter.com/hashtag/Texans?src=hash">#Texans</a> per <a href="https://twitter.com/NEPD_Loyko">@NEPD_Loyko</a></p>— PDS (@PatDStat) <a href="https://twitter.com/PatDStat/status/594652666480865281">May 3, 2015</a></blockquote> <script async src="//platform.twitter.com/widgets.js" charset="utf-8"></script>
<blockquote class="twitter-tweet" lang="en"><p lang="en" dir="ltr"><a href="https://twitter.com/hashtag/Texans?src=hash">#Texans</a> sign Auburn OL Chad Slade.</p>— PDS (@PatDStat) <a href="https://twitter.com/PatDStat/status/594653238483226624">May 3, 2015</a></blockquote> <script async src="//platform.twitter.com/widgets.js" charset="utf-8"></script>