Lightning Assistive search explained in this article (http://www.jitendrazaa.com/blog/salesforce/lightning-component-for-wikipedia-search/) updated for account search

AccSearch.cmp

 <aura:component controller="AccSearchController" implements="force:appHostable,flexipage:availableForAllPageTypes">
    <aura:attribute name="accSearchText" type="String"/>
    <aura:attribute name="resultLimit" type="Integer" default="4"/> 
	
	<div class="slds-card">
		<div class="slds-card__header slds-grid">
			<div class="slds-media slds-media--center slds-has-flexi-truncate">
				<div class="slds-media__figure">
					<lightning:icon iconName="custom:custom68"></lightning:icon>
			  	</div>

				<div class="slds-media__body">
					<h2 class="slds-text-heading--small slds-truncate">Account Search</h2>
				</div>
	    	</div>
	  	</div>
		
		<div class="slds-card__body slds-box slds-theme--default">
			<div class="slds-grid slds-wrap">
				<div class="slds-col slds-size--10-of-12">
	          		<ui:inputText value="{!v.accSearchText}" placeholder="Hit enter button to search" class="slds-input" keyup="{!c.searchAccs}"/>    
	          	</div>
				<div class="slds-col slds-size--2-of-12">
					<button class="slds-m-left--small slds-button slds-button--icon-border-filled slds-button--icon-small" onclick="{!c.searchAccsOnButton}">
						<lightning:icon iconName="utility:search"></lightning:icon>
					  <span class="slds-assistive-text">Settings</span>
					</button>
	          	</div>
				<div class="slds-col slds-size--10-of-12 slds-p-top--large">
					<ul id="resultPlaceHolder" class="slds-list--vertical slds-has-cards slds-has-inline-block-links--space">
	                	  <!-- This is placeholder to render Account Search results -->
	              	</ul>
				</div>
				<div class="slds-col slds-size--2-of-12">
				</div>
        	</div>
		</div>
	</div>
</aura:component>

AccSearch.design

<design:component>
	<design:attribute name="resultLimit" label="Result Limit" description="Total number of results to display" />
</design:component>

AccSearchController.cls

public class AccSearchController {

    @AuraEnabled
    public static String searchAccounts(String searchText, Integer limitInt){
    	Integer limitInteger = Integer.valueOf(limitInt);
        List<Account> accList = Database.query('SELECT Id,Name FROM Account WHERE Name LIKE ' + '\'%' + searchText + '%\'' + ' LIMIT ' + limitInteger);
        return JSON.serialize(accList);
    }
}

AccSearchController.js

({
	searchAccs : function(component, event, helper) { 
        if(event.getParams().keyCode == 13){   
            helper.accSearch(component.get('v.accSearchText'),component, helper); 
        }
	},
    searchAccsOnButton : function(component, event, helper){ 
        helper.accSearch(component.get('v.accSearchText'),component, helper); 
    }
})

AccSearchHelper.js

({
	accSearch : function(txtToSearch , component, helper) {
        
        var action = component.get('c.searchAccounts');
        var resLimit = component.get('v.resultLimit');
        action.setParams({
            searchText : txtToSearch,
            limitInt : resLimit
        });
        
        action.setCallback(this, function(a) {
            if (a.getState() === 'SUCCESS') {
            	console.log(a.getReturnValue());
                helper.parseResult(a.getReturnValue(),helper);                
            }  
        });
        $A.enqueueAction(action);   
	},
    parseResult : function(res,helper){
        var retJSON = JSON.parse(res);
        
        console.log(retJSON);

        domSearch = document.getElementById('resultPlaceHolder');
        while (domSearch.firstChild) {
            domSearch.removeChild(domSearch.firstChild);
        }
        
        for(var i=0 ; i<retJSON.length ; i++)
        {
           helper.createChildNodes(domSearch, retJSON[i].Name,window.location.origin + '/'+ retJSON[i].Id); 
        }
        
    },
    
    createChildNodes : function(domSearch,title,url){ 
        var res_li = document.createElement('li');
        res_li.setAttribute('class', 'slds-list__item'); 
        
        var link = document.createElement('a');
        link.setAttribute('href', url);
        link.innerText = title;
        
        res_li.appendChild(link);
        domSearch.appendChild(res_li); 
    }
})

HelloWorldApp.app

<aura:application extends="force:slds">
	<c:AccSearch></c:AccSearch>
</aura:application>