All of these siddurim were tested in Android 4.04 and some were tested on 2.3 and 4.04, as our test phone got upgraded during the testing phase.  Before choosing any siddur below, it's important to know that they are best for those already quite familiar with the tefilos.  If someone is new to davening (praying) in Hebrew, they will easily get confused by most of the products below, the notable exception being the Smart Siddur, which displays the correct prayer each day.  Only one of these products has perfect nekudot (vowels) (and some don't have any at all!) and one unfamiliar with the nusach will get confused easily and possibly mispronounce words.  Until some of the big issues get fixed (most notably the issue with nekudos), we do not have "Top Pick" in this category at this time of this post.

Note: Newcomers to Jewish prayer should purchase a printed prayer book (see artscroll.com for Sfard or Ashkenaz or visit your local Jewish bookstore).  

Overview: This is a scanned weekday siddur for Lubavitch. 


+Reminder to say "Ya'aleh V'yavo" on Rosh Chodesh
+Built-in simple zmanim program
+Includes Birkat Hamazon and other blessings
+Includes silent mode and even "airplane mode" to shut down wireless communications while davening
+Full screen mode covers over the notifications at the top of the screen to help keep distractions at bay
+ICS friendly


-Utilizes scanned text 
-No index (one must scroll to where he wants to be in the tefilla and cannot "jump" to tachanun or aleinu, for instance
-Some of the smaller text can be hard to read -- has zoom feature but not a scalable zoom -- when zoomed in (long press) too much left-and-right scrolling is necessary
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Type: Application

-Some strange nusach issues in all nusachim. For example: No "Shir Hamalos" before BirKat HaMazon.  "Ya'aleh V'yavo" is only available for chol hamoed Pesach in BirKat HaMazon, even though the normal paragraph is shown in the amida. (Author had no good response to this issue and has no intention to fix.)
-No real indexing of tefillos.  Only Shaharit has three parts.  All other tefillot have just one part and require scrolling to get to, let's say, tachanun.
-Vowels occasionally missing from words and almost entire paragraphs.
-No anti-distraction options


Verdict: Aside from some small annoying issues, this is one of the most practically usable siddur apps here, mainly due to the easy legibility of the text.  Paid version allows settings savings, but this app has very little in the way of settings in the first place.
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Verdict: The text is readable, the developer is very responsive and takes the development of the app very seriously.  In time, they plan on releasing a version that acts like the "smart siddur" above and includes multiple nusachim.  Bottom line: A very usable siddur on its way up.

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Nusach: Ashkenaz, Sefarad, Ari, Edut Hamizrach.
Overview: This siddur comes packed with the three daily tefillot for four nusachim, plus birkat hamazon, tefilat haderech and Meguillat [SIC] Esther.  There are 18 different choices in all. It also starts up with a launcher that includes complete Torah and Tehillim (not reviewed on this page).

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Type: Application

Overview:  Easy siddur lives up to its name with being a very simple down-to-earth Ashkenaz partial siddur

+Very simple interface.
+Easy to touch large red buttons toggle parts of tefilla that one may or may not need to say.
+Works with ICS

-Just micha, ma'ariv and after blessings for bread and cake.
-No vowels altogether.
-Some unnecessary bold lettering can lead to confusion (if it's a section heading or actual tefilla) since there are no vowels in any event.
-Except for "ya'aleh v'yavo" there are no additions for any special days at all -- not Channukah and Purim, not fast days, and not even the Ten Days of Repentance.
-No shir hamalos or "al naharos bavel" before benching

Verdict:  Great for a quick jump to tefilla for one who is already familiar with the nusach.  This can't be the only siddur to be installed on your device as there are just too many "special" days in the Jewish calendar where one is still likely to be stuck without a siddur, and this just doesn't have those options.

Overview: Not a winner!  Shows up backwards on our test (American phone)

-Hebrew is backwards, which makes it useless
-Banner ads for "Free Messianic Bible" leave much to be desired
-Will not load in ICS (Android 4.0)

Type: Application and Widget

Overview: This siddur seems best for those that live in Israel, but has many flaws

Verdict: The author said in early 2009 that a hopeful change to Android would allow for a proper text version, and it's 2012 and it's still an odd-ball graphics version that's hard to navigate.  For now, we'd move on to a different siddur.