brainstorming:

• https://bubbl.us/
• http://www.wisemapping.com/
• https://play.google.com/store/apps/details?id=de.softxperience.android.noteeverything&feature=search_result#?t=W251bGwsMSwxLDEsImRlLnNvZnR4cGVyaWVuY2UuYW5kcm9pZC5ub3RlZXZlcnl0aGluZyJd
• http://wridea.com/

dictionaries/grammar:

• http://onelook.com/reverse-dictionary.shtml
• http://chir.ag/projects/tip-of-my-tongue/
• http://www.rhymezone.com/
• http://thesaurus.com/
• http://www.writtensound.com/index.php

focusing:

• http://www.baara.com/q10/
• http://www.ommwriter.com/
• http://www.finaldeadline.co.uk/index.php
• http://writeordie.com/

prompts:

• http://www.creativewritingprompts.com/
• http://thestorystarter.com/
• http://www.seventhsanctum.com/generate.php?Genname=quickstory

writer's block:

• http://www.therenegadewriter.com/2007/10/28/busting-your-writing-rut/
• http://www.writersdigest.com/editor-blogs/guide-to-literary-agents/7-ways-to-overcome-writers-block