Creating PDF files from images

In Apple's own support forum, while answering (link) a question on how PDF files should be created from images from the Camera Roll of the device, I've tested quite a lot of PDF readers / editors for iOS - basically, the ones I've elaborated on in my Ultimate PDF Reader Roundup (link) and some more. Here are my findings:

PDF readers supporting creating PDF files from images:

PDF Reader Pro (Yuyao; link; $6) (can convert single images only - that is, it can't include more than one source image in a single target PDF file!)

Master your iPhone in one minute a day:

Sign up to iPhone Life's Tip of the Day Newsletter and we'll send you a tip each day to save time and get the most out of your iPhone or iPad.

PDF Reader (Kdan Mobile Software; link; $5) (several in one! Just follow the built-in help at “i” icon at the bottom left > PDF Scanner)

PDF Reader Pro (iTech; link; $10) (multiple export; tap the “Scan” icon at the bottom center, tap the film cartridge icon in the bottom left; tap all images you want to import; when you're finished, tap “Make PDF” (second icon on the bottom left)

Readers that don't support the conversion:

GoodReader (for iPad)
QuickOffice Pro HD
PDF Comrade
iPDFReader by Tatvasoft
PDF Juggler
PDF Viewer
DocsScan HD
PDF Reader
Easy PDF
File Viewer
iRead PDF  (Aji)
iAnnotate PDF
DocAS Reader
Adobe Reader

Crashes under iOS 5.1.1:

Quick PDF+

NB.: as I've also explained in the thread, many apps natively support PDF output. For example, Apple's own “Numbers” is not only able to export / mail PDF files from inside the app (unfortunately, there's no “Send to” inside to transfer the file to another app inside the same iDevice – this has always been a problem), but also do it textually – as opposed to just making a screenshot of the current screen and making a PDF of it by accessing the screenshot in the Camera Roll in a PNG->PDF-conversion capable PDF.

A screenshot of Numbers asking for the export / mail / upload file format (it's there that you need to select PDF - I've annotated the PDF export icon with a red rectangle; click the image for the original-sized version):

Master your iPhone in one minute a day: Sign up here to get our FREE Tip of the Day delivered right to your inbox.

<p>Werner Ruotsalainen is an iOS and Java programming lecturer who is well-versed in programming, hacking, operating systems, and programming languages. Werner tries to generate unique articles on subjects not widely discussed. Some of his articles are highly technical and are intended for other programmers and coders.</p>
<p>Werner also is interested in photography and videography. He is a frequent contributor to not only mobile and computing publications, but also photo and video forums. He loves swimming, skiing, going to the gym, and using his iPads. English is one of several languages he speaks.</p>