// Dark
self.view.backgroundColor = [UIColor viewFlipsideBackgroundColor];
// Light
self.view.backgroundColor = [UIColor underPageBackgroundColor];

You can check other default patterns at iPhone Development Wiki.

- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view {
    UITableViewCell *cell = (UITableViewCell *)view;

    if (cell == nil) {
	cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:nil];
	[cell setBackgroundColor:[UIColor clearColor]];
	[cell setBounds: CGRectMake(0, 0, cell.frame.size.width -20 , 44)];
	cell.tab = row
	UITapGestureRecognizer *singleTapGestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(toggleSelection:)];
	singleTapGestureRecognizer.numberOfTapsRequired = 1;
	[cell addGestureRecognizer:singleTapGestureRecognizer];
    }

    if ([selectedItems indexOfObject:[NSNumber numberWithInt:row]] != NSNotFound) {
        [cell setAccessoryType:UITableViewCellAccessoryCheckmark];
    } else {
        [cell setAccessoryType:UITableViewCellAccessoryNone];
    }
    cell.textLabel.text = [datasource objectAtIndex:row];

	return cell;
}

- (void)toggleSelection:(UITapGestureRecognizer *)recognizer {
    NSNumber *row = [NSNumber numberWithInt:recognizer.view.tag];
    NSUInteger index = [selectedItems indexOfObject:row];
    if (index != NSNotFound) {
        [selectedItems removeObjectAtIndex:index];
        [(UITableViewCell *)(recognizer.view) setAccessoryType:UITableViewCellAccessoryNone];
    } else {
        [selectedItems addObject:row];
        [(UITableViewCell *)(recognizer.view) setAccessoryType:UITableViewCellAccessoryCheckmark];
    }
}

Just add NSMutableArray *selectedItems and NSArray *datasource to interface and you’re ready to go.

• TWTweetComposeViewController – simple composer, similar to SMS and Email composers
• TWRequest – NSURLRequest like class for Twitter requests

First one is great when you just want to set Twitter status and you can read how to use it at Ray Wenderlich’s blog.
If you need to do more, like fetch user’s followers or get his avatar, you need to do a little bit more code.

First you have to access user’s accounts via ACAccountStore class. You do this by sending requestAccessToAccountsWithType:withCompletionHandler: message to ACAccountStore instance. This will show a dialog, asking user to allow access to his Twitter accounts. Then if it’s all ok, you just store them in NSArray.
It’s also important to observe ACAccountStoreDidChangeNotification, so you can update accounts when user adds or removes them from system.

- (void)initTwitter {
	// Check if current iOS supports Twitter
	if (NSClassFromString(@"ACAccountStore")) {
		accountStore = [[ACAccountStore alloc] init];
		ACAccountType *twitterType = [accountStore accountTypeWithAccountTypeIdentifier:ACAccountTypeIdentifierTwitter];
		// This will show a dialog asking user to allow access to his Twitter accounts
		[accountStore requestAccessToAccountsWithType:twitterType
								withCompletionHandler:^(BOOL granted, NSError *error) {
									if (granted) {
										ACAccountType *twitterType = [accountStore accountTypeWithAccountTypeIdentifier:ACAccountTypeIdentifierTwitter];
										// twitterAccounts array will hold all user's Twitter accounts
										twitterAccounts = [accountStore accountsWithAccountType:twitterType];
									} else {
										// User denied access to his Twitter accounts
									}
								}];

		// When user adds/removes accounts, your app have to be notified about that and update its UI
		[[NSNotificationCenter defaultCenter] addObserver:self
												 selector:@selector(twitterAccountsChanged:)
													 name:ACAccountStoreDidChangeNotification object:nil];
	} else {
		// This iOS verion doesn't support Twitter. Use 3rd party library
	}
}

- (void)twitterAccountsChanged:(NSNotification *)notif {
    ACAccountType *twitterType = [accountStore accountTypeWithAccountTypeIdentifier:ACAccountTypeIdentifierTwitter];
    [accountStore requestAccessToAccountsWithType:twitterType
                            withCompletionHandler:^(BOOL granted, NSError *error) {
        if (granted) {
            ACAccountType *twitterType = [accountStore accountTypeWithAccountTypeIdentifier:ACAccountTypeIdentifierTwitter];
            twitterAccounts = [accountStore accountsWithAccountType:twitterType];
        }
   }];
}

After this, you just send a request to Twitter using one of user’s accounts:

if (NSClassFromString(@"ACAccountStore")) {
	// https://dev.twitter.com/docs/api
	NSURL *url = [NSURL URLWithString:@"http://api.twitter.com/1/statuses/update.json"];
	NSDictionary *parameters = [NSDictionary dictionaryWithObjectsAndKeys:@"Hello world!", @"status", nil];

	TWRequest *tweet = [[TWRequest alloc] initWithURL:url parameters:parameters requestMethod:TWRequestMethodPOST];
	// Set account selected by user
	tweet.account = [twitterAccounts objectAtIndex:0];
	[tweet performRequestWithHandler:^(NSData *responseData, NSHTTPURLResponse *urlResponse, NSError *error) {
		// Handle errors or success
	}];
}

See? It isn’t that bad :) You can also add Twitter accounts to system and couple more cool things, but you can lean this from Session 124: Twitter Integration from WWDC 2011 by Glen Steele and Scott Herz.

1. Remove all the non-ARC code from the project
2. Create new “Cocoa Touch Static Library” (or “Cocoa Library” for Mac projects) target
3. Uncheck “Use Automatic Reference Counting“
4. Add your non-ARC to your library (there should be a folder in top level of Xcode Navigator with your library name – add them here)
5. Go to Build Phases of your main target and:
   • Remove non-ARC code from Compile Sources phase
   • Add your library target to Target Dependencies phase
   • Drag your library product (it’s in last group in Navigator) to Link Binary With Libraries phase
6. Go to Build Phases of your library target and add all *.m files from library to Compile Sources phase
7. Compile and enjoy your non-ARC code in an ARC project :)

Note: If building library still gives you errors about ARC, go to Build Settings of library and set Objective-C Automatic Reference Counting to No (sometimes Xcode ignores unchecking it when creating library).

buildNumber=$(/usr/libexec/PlistBuddy -c "Print CFBundleVersion" ${PROJECT_DIR}/${PROJECT_NAME}/${PROJECT_NAME}-Info.plist)
buildNumber=$(($buildNumber + 1))
/usr/libexec/PlistBuddy -c "Set :CFBundleVersion $buildNumber" ${PROJECT_DIR}/${PROJECT_NAME}/${PROJECT_NAME}-Info.plist

Now just add “Run Script” build phase with this script (remember to move it before “Copy Bundle Resources” phase) and set your CFBundleVersion to an integer.

After PHP, Flex/ActionScript and Python/Django I moved to ObjC and Cocoa (there’s still some PHP and Python though). You may remember the name petiteDev as a brand under which I was developing new products. Well now it’s an official enterprise. Web projects will still be launched under it, but iOS/Mac apps have their own brand. And the brand is Appsome! True story ;) There are three Mac apps for now: ScreenTap (color picker and screen ruler), Lagometer (connection monitor) and nanoTunes (smallest music player in Mac App Store). More will be coming soon.

There’s also one project: I enjoyed it. It’s a movie recommendation site with an unique algorithm and very simple UI. This project is crowd funded, so if you want to tip in, feel free to do it at IndieGoGo. Watch a promo movie that explains the idea:

Well, that’s all for now, but stay tuned for new and exciting projects ;)